Summary of findings 6. Sedatives compared to placebo for preventing nausea and vomiting in women undergoing regional anaesthesia for caesarean section.
| Sedatives compared to placebo for preventing nausea and vomiting in women undergoing regional anaesthesia for caesarean section | ||||||
| Patient or population: women undergoing regional anaesthesia for caesarean section Setting: hospitals across low‐, middle‐ and high‐income countries Intervention: sedatives Comparison: placebo | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | № of participants (studies) | Certainty of the evidence (GRADE) | Comments | |
| Risk with placebo | Risk with sedatives (F) | |||||
| Nausea ‐ intraoperative | Study population | RR 0.65 (0.51 to 0.82) | 593 (8 RCTs) | ⊕⊕⊕⊝ MODERATE 1 | ||
| 375 per 1000 | 244 per 1000 (191 to 308) | |||||
| Vomiting ‐ intraoperative | Study population | RR 0.35 (0.24 to 0.52) | 593 (8 RCTs) | ⊕⊕⊕⊝ MODERATE 2 | ||
| 294 per 1000 | 103 per 1000 (71 to 153) | |||||
| Nausea ‐ postoperative | Study population | RR 0.25 (0.09 to 0.71) | 145 (2 RCTs) | ⊕⊝⊝⊝ VERY LOW 3 4 | ||
| 441 per 1000 | 110 per 1000 (40 to 313) | |||||
| Vomiting ‐ postoperative | Study population | RR 0.09 (0.03 to 0.28) | 145 (2 RCTs) | ⊕⊕⊝⊝ LOW 5 | ||
| 356 per 1000 | 32 per 1000 (11 to 100) | |||||
| *The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; RR: Risk ratio. | ||||||
| GRADE Working Group grades of evidence High certainty: we are very confident that the true effect lies close to that of the estimate of the effect. Moderate certainty: we are moderately confident in the effect estimate; the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low certainty: our confidence in the effect estimate is limited; the true effect may be substantially different from the estimate of the effect. Very low certainty: we have very little confidence in the effect estimate; the true effect is likely to be substantially different from the estimate of effect. | ||||||
1 Downgrade 1 for risk of bias: 56% of data from studies with low risk of selection bias.
2 Downgrade 1 for risk of bias: 75% of data were from studies with unclear selection bias.
3 Downgrade 1 for inconsistency: moderate heterogeneity. I2 = 58%. Chi2 P = 0.09.
4 Downgrade 2 for imprecision: low number of events ‐ 37 and low number of participants 145. Wide CI though a reasonable distance from line of no difference.
5 Downgrade 2 for imprecision: low number of events ‐ 23 and low number of participants 145. Wide CI but a good distance from the line of no difference although the data of high effectiveness comes from just one study of 44 women.